function ddtabcontent(tabinterfaceid){
this.tabinterfaceid=tabinterfaceid //ID of Tab Menu main container
this.tabs=document.getElementById(tabinterfaceid).getElementsByTagName("a") //Get all tab links within container
this.enabletabpersistence=true
this.hottabspositions=[] //Array to store position of tabs that have a "rel" attr defined, relative to all tab links, within container
this.currentTabIndex=0 //Index of currently selected hot tab (tab with sub content) within hottabspositions[] array
this.subcontentids=[] //Array to store ids of the sub contents ("rel" attr values)
this.revcontentids=[] //Array to store ids of arbitrary contents to expand/contact as well ("rev" attr values)
this.selectedClassTarget="link" //keyword to indicate which target element to assign "selected" CSS class ("linkparent" or "link")
}
ddtabcontent.getCookie=function(Name){
var re=new RegExp(Name+"=[^;]+", "i"); //construct RE to search for target name/value pair
if (document.cookie.match(re)) //if cookie found
 return document.cookie.match(re)[0].split("=")[1] //return its value
return ""
}
ddtabcontent.setCookie=function(name, value){
document.cookie = name+"="+value+";path=/" //cookie value is domain wide (path=/)
}
ddtabcontent.prototype={

expandit:function(tabid_or_position){ //PUBLIC function to select a tab either by its ID or position(int) within its peers
 this.cancelautorun() //stop auto cycling of tabs (if running)
 var tabref=""
 try{
  if (typeof tabid_or_position=="string" && document.getElementById(tabid_or_position).getAttribute("rel")) //if specified tab contains "rel" attr
   tabref=document.getElementById(tabid_or_position)
  else if (parseInt(tabid_or_position)!=NaN && this.tabs[tabid_or_position].getAttribute("rel")) //if specified tab contains "rel" attr
   tabref=this.tabs[tabid_or_position]
 }
 catch(err){alert("Invalid Tab ID or position entered!")}
 if (tabref!="") //if a valid tab is found based on function parameter
  this.expandtab(tabref) //expand this tab
},
cycleit:function(dir, autorun){ //PUBLIC function to move foward or backwards through each hot tab (tabinstance.cycleit('foward/back') )
 if (dir=="next"){
  var currentTabIndex=(this.currentTabIndex<this.hottabspositions.length-1)? this.currentTabIndex+1 : 0
 }
 else if (dir=="prev"){
  var currentTabIndex=(this.currentTabIndex>0)? this.currentTabIndex-1 : this.hottabspositions.length-1
 }
 if (typeof autorun=="undefined") //if cycleit() is being called by user, versus autorun() function
  this.cancelautorun() //stop auto cycling of tabs (if running)
 this.expandtab(this.tabs[this.hottabspositions[currentTabIndex]])
},
setpersist:function(bool){ //PUBLIC function to toggle persistence feature
  this.enabletabpersistence=bool
},
setselectedClassTarget:function(objstr){ //PUBLIC function to set which target element to assign "selected" CSS class ("linkparent" or "link")
 this.selectedClassTarget=objstr || "link"
},
getselectedClassTarget:function(tabref){ //Returns target element to assign "selected" CSS class to
 return (this.selectedClassTarget==("linkparent".toLowerCase()))? tabref.parentNode : tabref
},
urlparamselect:function(tabinterfaceid){
 var result=window.location.search.match(new RegExp(tabinterfaceid+"=(\\d+)", "i")) //check for "?tabinterfaceid=2" in URL
 return (result==null)? null : parseInt(RegExp.$1) //returns null or index, where index (int) is the selected tab's index
},
expandtab:function(tabref){
 var subcontentid=tabref.getAttribute("rel") //Get id of subcontent to expand
 //Get "rev" attr as a string of IDs in the format ",john,george,trey,etc," to easily search through
 var associatedrevids=(tabref.getAttribute("rev"))? ","+tabref.getAttribute("rev").replace(/\s+/, "")+"," : ""
 this.expandsubcontent(subcontentid)
 this.expandrevcontent(associatedrevids)
 for (var i=0; i<this.tabs.length; i++){ //Loop through all tabs, and assign only the selected tab the CSS class "selected"
  this.getselectedClassTarget(this.tabs[i]).className=(this.tabs[i].getAttribute("rel")==subcontentid)? "selected" : ""
 }
 if (this.enabletabpersistence) //if persistence enabled, save selected tab position(int) relative to its peers
  ddtabcontent.setCookie(this.tabinterfaceid, tabref.tabposition)
 this.setcurrenttabindex(tabref.tabposition) //remember position of selected tab within hottabspositions[] array
},
expandsubcontent:function(subcontentid){
 for (var i=0; i<this.subcontentids.length; i++){
  var subcontent=document.getElementById(this.subcontentids[i]) //cache current subcontent obj (in for loop)
  subcontent.style.display=(subcontent.id==subcontentid)? "block" : "none" //"show" or hide sub content based on matching id attr value
 }
},
expandrevcontent:function(associatedrevids){
 var allrevids=this.revcontentids
 for (var i=0; i<allrevids.length; i++){ //Loop through rev attributes for all tabs in this tab interface
  //if any values stored within associatedrevids matches one within allrevids, expand that DIV, otherwise, contract it
  document.getElementById(allrevids[i]).style.display=(associatedrevids.indexOf(","+allrevids[i]+",")!=-1)? "block" : "none"
 }
},
setcurrenttabindex:function(tabposition){ //store current position of tab (within hottabspositions[] array)
 for (var i=0; i<this.hottabspositions.length; i++){
  if (tabposition==this.hottabspositions[i]){
   this.currentTabIndex=i
   break
  }
 }
},
autorun:function(){ //function to auto cycle through and select tabs based on a set interval
 this.cycleit('next', true)
},
cancelautorun:function(){
 if (typeof this.autoruntimer!="undefined")
  clearInterval(this.autoruntimer)
},
init:function(automodeperiod){
 var persistedtab=ddtabcontent.getCookie(this.tabinterfaceid) //get position of persisted tab (applicable if persistence is enabled)
 var selectedtab=-1 //Currently selected tab index (-1 meaning none)
 var selectedtabfromurl=this.urlparamselect(this.tabinterfaceid) //returns null or index from: tabcontent.htm?tabinterfaceid=index
 this.automodeperiod=automodeperiod || 0
 for (var i=0; i<this.tabs.length; i++){
  this.tabs[i].tabposition=i //remember position of tab relative to its peers
  if (this.tabs[i].getAttribute("rel")){
   var tabinstance=this
   this.hottabspositions[this.hottabspositions.length]=i //store position of "hot" tab ("rel" attr defined) relative to its peers
   this.subcontentids[this.subcontentids.length]=this.tabs[i].getAttribute("rel") //store id of sub content ("rel" attr value)
   this.tabs[i].onclick=function(){
    tabinstance.expandtab(this)
    tabinstance.cancelautorun() //stop auto cycling of tabs (if running)
    return false
   }
   if (this.tabs[i].getAttribute("rev")){ //if "rev" attr defined, store each value within "rev" as an array element
    this.revcontentids=this.revcontentids.concat(this.tabs[i].getAttribute("rev").split(/\s*,\s*/))
   }
   if (selectedtabfromurl==i || this.enabletabpersistence && selectedtab==-1 && parseInt(persistedtab)==i || !this.enabletabpersistence && selectedtab==-1 && this.getselectedClassTarget(this.tabs[i]).className=="selected"){
    selectedtab=i //Selected tab index, if found
   }
  }
 } //END for loop
 if (selectedtab!=-1) //if a valid default selected tab index is found
  this.expandtab(this.tabs[selectedtab]) //expand selected tab (either from URL parameter, persistent feature, or class="selected" class)
 else //if no valid default selected index found
  this.expandtab(this.tabs[this.hottabspositions[0]]) //Just select first tab that contains a "rel" attr
 if (parseInt(this.automodeperiod)>500 && this.hottabspositions.length>1){
  this.autoruntimer=setInterval(function(){tabinstance.autorun()}, this.automodeperiod)
 }
} //END int() function
} //END Prototype assignment
